Cryptosporidium within a One Health Framework: A Comprehensive Review of Public Health Impact, Environmental Concerns, and Emerging Strategies for Prevention and Treatment

Abstract

Cryptosporidium species are globally distributed parasites and major cause of cryptosporidiosis, a diarrheal disease that disproportionately affects immunocompromised individuals and young children in low-resource settings. Cryptosporidium is widely regarded as a critical contaminant of drinking water and is strongly associated with an increased risk of waterborne disease, posing a serious threat to public health. Furthermore, agricultural environments can serve as sources of contamination with Cryptosporidium oocysts through fecal material originating from both humans and animals. Despite their major zoonotic relevance, critical gaps remain in understanding their true public health burden, transmission pathways, and ways to effectively translate emerging knowledge into prevention and treatment strategies. Currently, nitazoxanide is the only FDA-approved treatment for cryptosporidiosis; however, its efficacy in vulnerable populations remains limited. Safe and effective chemotherapeutics are urgently needed; however drug evaluation methods lack standardization, and no reliable vaccine surrogates capable of inducing protective immunity have been identified. Additionally, the identification of vaccination surrogates that confer protective immune responses against Cryptosporidium infection remains an unresolved need. In addition, Cryptosporidium diagnosis relies on fecal microscopy, antigen-based assays for rapid detection, and molecular methods, such as PCR, for sensitive species identification and genotyping. Emerging approaches, including next-generation sequencing, promise improved multiplex detection and epidemiological resolution but require further integration into routine clinical laboratory workflow. This review summarizes the advances in Cryptosporidium therapeutics, including herbal, chemical, and pharmaceutical approaches, as well as chemical agents utilized for water treatment and environmental control, highlighting associated safety concerns as well as diagnostics. It further outlines priority areas for future research, such as the development of novel drug candidates, host-targeted therapies, and next-generation vaccine platforms. Finally, it underscores the complex, multifactorial challenges of controlling Cryptosporidium and calls for a One Health approach that integrates human, animal, and environmental health to mitigate its global impact.